This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Determine the relative importance of different T cell activation components in the induction of HIV replication, and the influence of viral early gene product, Nef, on these required activation events.